From 6ff4a25bf37b1a96b2664aa6d6d431b374a08c7e Mon Sep 17 00:00:00 2001
From: Sebastian Seedorf <sseedorf@eclassifiedsgroup.com>
Date: Fri, 17 Dec 2021 11:29:35 +0100
Subject: [PATCH] Day 16

---
 day16/generator.py | 86 ++++++++++++++++++++++++++++++++++++++++++++++
 day16/input.txt    | 11 ++++++
 day16/part1.py     | 18 ++++++++++
 day16/part2.py     | 39 +++++++++++++++++++++
 day16/shared.py    | 48 ++++++++++++++++++++++++++
 5 files changed, 202 insertions(+)
 create mode 100644 day16/generator.py
 create mode 100644 day16/input.txt
 create mode 100644 day16/part1.py
 create mode 100644 day16/part2.py
 create mode 100644 day16/shared.py

diff --git a/day16/generator.py b/day16/generator.py
new file mode 100644
index 0000000..939e619
--- /dev/null
+++ b/day16/generator.py
@@ -0,0 +1,86 @@
+import random
+
+def int_to_bin(num, l):
+    return bin(num)[2:].zfill(l)
+
+def literal(ver, num):
+    bin_num = bin(num)[2:]
+    bin_num = bin_num.zfill((len(bin_num)+3) // 4 * 4)
+    return int_to_bin(ver, 3) + int_to_bin(4, 3) + ''.join(('1' if i+4 < len(bin_num) else "0") + bin_num[i:i+4] for i in range(0, len(bin_num), 4))
+
+def sub_by_length(ver, op, subs):
+    bin_sub = ''.join(subs)
+    bin_len = int_to_bin(len(bin_sub), 15)
+    return int_to_bin(ver, 3) + int_to_bin(op, 3) + '0' + bin_len + bin_sub
+
+def sub_by_amount(ver, op, subs):
+    bin_sub = ''.join(subs)
+    bin_len = int_to_bin(len(subs), 11)
+    return int_to_bin(ver, 3) + int_to_bin(op, 3) + '1' + bin_len + bin_sub
+
+def bin_to_hex(bin_num):
+    pad_len = (len(bin_num)+7) // 8 * 8 - len(bin_num)
+    bin_num = bin_num + '0' * pad_len
+    return ''.join(hex(int(bin_num[i:i+4], 2))[2:] for i in range(0, len(bin_num), 4)).upper()
+
+print(bin_to_hex(
+    literal(6, 2021)
+) == 'D2FE28')
+print(bin_to_hex(
+    sub_by_length(1, 6, [
+        literal(6, 10),
+        literal(2, 20)
+    ])
+) == '38006F45291200')
+print(bin_to_hex(
+    sub_by_amount(7, 3, [
+        literal(2, 1),
+        literal(4, 2),
+        literal(1, 3)
+    ])
+) == 'EE00D40C823060')
+print(bin_to_hex(
+    sub_by_amount(4, 2, [
+        sub_by_amount(1, 2, [
+            sub_by_length(5, 2, [
+                literal(6, 15)
+            ])
+        ])
+    ])
+) == '8A004A801A8002F478')
+print(bin_to_hex(
+    sub_by_amount(3, 0, [
+        sub_by_length(0, 0, [
+            literal(0, 10),
+            literal(5, 11)
+        ]),
+        sub_by_amount(1, 0, [
+            literal(0, 12),
+            literal(3, 13)
+        ])
+    ])
+) == '620080001611562C8802118E34')
+print(bin_to_hex(
+    sub_by_length(3, 0, [
+        sub_by_length(0, 0, [
+            literal(0, 1000),
+            literal(5, 51641)
+        ]),
+        sub_by_length(1, 0, [
+            literal(0, 65213),
+            literal(3, 213511)
+        ]),
+        sub_by_length(1, 0, [
+            literal(0, 65213),
+            literal(3, 213511)
+        ]),
+        sub_by_length(1, 0, [
+            literal(0, 65213),
+            literal(3, 213511)
+        ]),
+        sub_by_length(1, 0, [
+            literal(0, 65213),
+            literal(3, 213511)
+        ])
+    ])
+))
diff --git a/day16/input.txt b/day16/input.txt
new file mode 100644
index 0000000..f063d2b
--- /dev/null
+++ b/day16/input.txt
@@ -0,0 +1,11 @@
+D2FE28
+38006F45291200
+EE00D40C823060
+8A004A801A8002F478
+620080001611562C8802118E34
+C0015000016115A2E0802F182340
+A0016C880162017C3686B18A3D4780
+#
+6006040002F127E459CCED24001C89FF6DAE4E9281C8003913FEDB5C9D250390007227FDB6B93A4A072000E44FFB6D7274940E
+#
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
diff --git a/day16/part1.py b/day16/part1.py
new file mode 100644
index 0000000..8490f50
--- /dev/null
+++ b/day16/part1.py
@@ -0,0 +1,18 @@
+#!/usr/bin/env python3
+from day16.shared import parse_packets
+
+lines = (x.strip() for x in open("input.txt"))
+
+
+def sum_version(exprs):
+    return sum(expr[0] + (sum_version(expr[2]) if isinstance(expr[2], list) else 0) for expr in exprs)
+
+
+for line in lines:
+    print("NEW LINE:", line)
+    if line[0] == '#':
+        continue
+    bin_string = ''.join(bin(int(c, 16))[2:].zfill(4) for c in line)
+    parsed = parse_packets(bin_string)
+    print(sum_version(parsed))
+
diff --git a/day16/part2.py b/day16/part2.py
new file mode 100644
index 0000000..c07e960
--- /dev/null
+++ b/day16/part2.py
@@ -0,0 +1,39 @@
+#!/usr/bin/env python3
+from functools import reduce
+from operator import mul
+
+from day16.shared import parse_packets
+
+lines = (x.strip() for x in open("input.txt"))
+
+
+def calc(expr):
+    _, op, value = expr
+    if op == 4:
+        return value
+    values = [calc(v) if isinstance(v, tuple) else v for v in value]
+    if op == 0:
+        return sum(values)
+    elif op == 1:
+        return reduce(mul, values)
+    elif op == 2:
+        return min(values)
+    elif op == 3:
+        return max(values)
+    elif op == 4:
+        return values
+    elif op == 5:
+        return 1 if values[0] > values[1] else 0
+    elif op == 6:
+        return 1 if values[0] < values[1] else 0
+    elif op == 7:
+        return 1 if values[0] == values[1] else 0
+
+
+for line in lines:
+    print("NEW LINE:", line)
+    if line[0] == '#':
+        continue
+    bin_string = ''.join(bin(int(c, 16))[2:].zfill(4) for c in line)
+    parsed = parse_packets(bin_string)
+    print(calc(parsed[0]))
diff --git a/day16/shared.py b/day16/shared.py
new file mode 100644
index 0000000..30f849f
--- /dev/null
+++ b/day16/shared.py
@@ -0,0 +1,48 @@
+def bin_to_int(bin_num):
+    return int(bin_num, 2)
+
+
+def parse_literal(bin_num):
+    res = ""
+    i = 0
+    while True:
+        res += bin_num[i+1:i+5]
+        i += 5
+        if bin_num[i-5] == '0':
+            break
+    return bin_to_int(res), i
+
+
+def parse_op(bin_num):
+    if bin_num[0] == '0':
+        length = bin_to_int(bin_num[1:16])
+        return parse_packets(bin_num[16:16+length]), length+16
+    else:
+        amount = bin_to_int(bin_num[1:12])
+        pkgs = []
+        i = 0
+        for _ in range(amount):
+            pkg, length = parse_packet(bin_num[12+i:])
+            pkgs.append(pkg)
+            i += length
+        return pkgs, 12+i
+
+
+def parse_packet(bin_num):
+    ver = bin_to_int(bin_num[:3])
+    op = bin_to_int(bin_num[3:6])
+    if op == 4:
+        value, length = parse_literal(bin_num[6:])
+    else:
+        value, length = parse_op(bin_num[6:])
+    return (ver, op, value), length + 6
+
+
+def parse_packets(bin_num):
+    pkgs = []
+    i = 0
+    while '1' in bin_num[i:]:
+        pkg, length = parse_packet(bin_num[i:])
+        pkgs.append(pkg)
+        i += length
+    return pkgs
\ No newline at end of file